town, comprising three resort communities (Le Châtelard-Montreux, Les Planches-Montreux, and Veytaux-Montreux; merged 1962) in Vaud canton, western Switzerland, extending 4 miles (6 km) along the eastern shore of Lake Geneva (Lac Léman). Its natural setting below mountains protecting it from northerly and easterly winds has made Montreux the lake's most fashionable health resort. The nearby 13th-century Château de Chillon, made famous by Lord Byron's poem “Prisoner of Chillon,” is one of Switzerland's best-known pieces of architecture. Montreux is on railway lines from Geneva and France to Italy via the Simplon Tunnel and is also a terminus of mountain railways. The tourist trade is important, while the villages of Caux, Chernex, Glion, Chamby, and Les Avants on terraces above Montreux depend mainly on agriculture and viticulture. Every year, Montreux hosts the well-known Montreux Jazz Festival. Pop. (2007 est.) 23,195.